/*
 * Copyright (c) 2017-2019 Tencent Group. All rights reserved.
 * License-Identifier: Apache-2.0
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may
 * not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

#include <string.h>
#include <stdio.h>

#include "qcloud_iot_import.h"
#include "utils_getopt.h"

static int	utils_opterr = 1;			/* if error message should be printed */
static int	utils_optind = 1;			/* index into parent argv vector */
static int	utils_optopt;				/* character checked for validity */
static int	utils_optreset = 1;        /* reset getopt */

char*		utils_optarg; /* argument associated with option */

int utils_getopt(int nargc, char* const* nargv, const char* options)
{

#define BADCH   (int)'?'
#define BADARG  (int)':'
#define EMSG    ""

	static char* place = EMSG;	/* option letter processing */
	const char* oli;			/* option letter list index */

	if (utils_optreset  || !*place)	/* update scanning pointer */
	{ 
		utils_optreset = 0;
	
		if (utils_optind >= nargc || *(place = nargv[utils_optind]) != '-') 
		{
			utils_optind = 1;
			utils_optreset = 1;
			place = EMSG;
			return (-1);
		}

		place++;
	}

	/* option letter okay? */
	if ((utils_optopt = (int)*place++) == (int)':' ||
		!(oli = strchr(options, utils_optopt))) {
		/*
		* if the user didn't specify '-' as an option,
		* assume it means -1.
		*/
		if (utils_optopt == (int)'-')
			return (-1);

		if (!*place)
			++utils_optind;

		if (utils_opterr && *options != ':')
			HAL_Printf("illegal option - %c\n", utils_optopt);

		return (BADCH);
	}

	if (*++oli != ':') {                    /* don't need argument */
		utils_optarg = NULL;
		if (!*place)
			++utils_optind;
	}
	else 
	{									/* need an argument */
		if (*place)                     /* no white space */
			utils_optarg = place;
		else if (nargc <= ++utils_optind) {   /* no arg */
			place = EMSG;
			if (*options == ':')
				return (BADARG);
			if (utils_opterr)
				HAL_Printf("option requires an argument - %c\n", utils_optopt);
			return (BADCH);
		}
		else                            /* white space */
			utils_optarg = nargv[utils_optind];

		place = EMSG;
		++utils_optind;
	}

	/* dump back option letter */
	return (utils_optopt);
}
